In File-Aid browse option use the below parameters:
Selection criteria usage ===> T
In the next screen, choose option 1 and give the values like the below..
Subsequent Selection Interval:
Records to select ===> 100
Records to skip ===> 300
and press enter and press PF3.
Now you are able to see the first 100 records and skip 300 records and next records from 400 to 500 and so on...
Note: A permutation combination of all the options will give you lot of other ways of selecting records.